Process for breaking petroleum emulsions



Patented Sept. '12, 1933 STATES PROCESS FOR BREAKING PETROLEUM EMULSIONS Melvin De Groote, St. Louis,

Keiser and Arthur F. Mo., assignors to Tre Groves, Mo., a corpo No Drawing. Application J1me Serial N 9 Claims.

This invention relates to the treatment of emulsions of mineral oil and water, such as petroleum emulsions, for the purpose of separating the oil from the water.

Petroleum emulsions are of the water-in-oil type, and comprise fine droplets of naturallyoccurring waters or brines, dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion. They are obtained from producing wells and from the bottoms of oil storage tanks, and are commonly referred to as Cut oil, Roily oil, Emulsified oil and Bottom settlings.

The object of our invention is to provide a novel, ine pensive and eflicient process for separating emulsions of the kind referred to into their component parts of oil and water or brine.

Briefly described, our process consists in subjecting a petroleum emulsion of the water-in-oil type, to the action of a treating agent or demulsifying agent of a particular kind or composition hereinafter described, thereby causing the emulsion to break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain in a quiescent state after such treatment. k

The treating agent or demulsifying agent used in our process consists of fatty sulfonic acids or their salts or esters, characterized by the fact. that 30 they are derived from unsaturated fatty acids and the sulfonic group is present or combined with the fatty radical at some carbon atom other than the two carbon atoms which are joined or linked by an unsaturated bond. We are aware of the fact that fatty sulfonic acids are members of a class of materials known as modified fatty acids, and that said modified fatty acids are used extensively in the demulsification of cut or emulsified oil. Sulfo fatty acids. or salts or esters thereof have 40 been in extensive use for a long time for breaking cut oil emulsions. Such sulfo acids included as their most important members, fatty acid sulfate and fatty sulfonic acids, as described in Industrial & Engineering Chemistry, Analytical Edition, volume 3, page 243 (1931).

The structural formula for written as follows:

CH3. (CH2) 7CH=CH.(CH2) 'zCOOH Ordinary oleic acid is characterized by the fact that the unsaturated bond (ethylene linkage) occurs between the ninth and tenth carbon atom, when one considers the carboxyl carbon atom as the first one. When sulfuric acid or, more preferably, sulfuric acid monohydrate, reacts with oleic oleic acid may be and Bernhard Wirtel, Webster Groves, tolite Company, Webster ration of Missouri acidv at relatively low temperatures, such as 35 (3., there is formed fatty acid sulfate by saturation of the unsaturated bond. This material is indicated by the following formula:

H /HSO4 omwmntuonromnooon If sulfonation takes place at or near the boiling point of water, there is formed a sulfonic acid, as shown by the following formula:

(See Fats, Natural and Synthetic, Myddleton & Barry, Benn, 1924, page 57.) The absence of the iodine number'in this compound clearly indicates the saturated character. In other words, the sulfonic acid radical that is formed is characterized by the fact that it is joined to one of the two carbon atoms, either No. 9 or No. 10, which are adjacent to the unsaturated bond.

Under certain conditions, it is possible to form sulfonic acids, not fatty acid sulfates, from unsaturated fatty acids, such as oleic acid or ricinoleic acid or their glyceride equivalents, such as olive oil or castor oil, in which the sulfonic acid radical is joined withor linked with some other carbon atom than either No. 9 or No. 10, which two are adjacent the unsaturated bond. In thesulfation or sulfonation of an unsaturated hydroxylated fatty body, such as castor oil, the reaction may take place at the alcoholiform hydroxyl, as well as at the ethylene linkage. Thus, for all practical purposes, one may say that the ordinary processes of sulfation or sulfonation are concerned with reactions which may involve at least one of two carbon atoms of unsaturated fatty acids containing an ethylene linkage, and may involve one of three carbon atoms if the fatty body is hydroxylated. Thus, the reaction may involve the two carbon atoms adjacent to. the ethylene linkage, and if the fatty material, such as castor oil, has an alcoholiform hydroxyl group, it may involve the carbon atom to which said alcoholiform hydroxyl group or radical is attached. Hence, these three carbon atoms, i. e., the two adjacent to the ethylene linkage, and the one to which the alcoholiform hydroxyl radical if present is attached, may be referred to as the conventional reactive carbon atoms, whereas, the other carbon atoms of the hydrocarbon chain are those which are not conventionally reactive. The reagents of the present application are concerned with sulfonic acid bodies characterized by the fact that the sulfonic group is at- Kalischer et al.

tached to a carbon atom other than the conventionally reactive carbon atoms. At first sight, it would appear that such materials might be obtained by sulfonation of a saturated fatty acid, such as stearic acid. If the sulfonation of stearic acid or tristearin produces such materials, they are unstable and decompose on contact with water (see Myddleton & Barry, v. s. p. 56). If an unsaturated fatty acid body, such as oleic acid, is

treated with sulfuric acid monohydrate under the proper conditions, there is produced the fatty acid sulfate of oleic acid, as indicated in U. S. Patent No. 1,835,404, dated December 8, 1931, to The sulfuric acid so entering into the reaction products saturates the unsaturated bond. If this material, that is, the fatty acid sulfate ester of oleic acid, is then treated with sulfur trioxide at relatively low temperatures, preferably below zero degree 0., in presence of a suitable inert solvent, there is formed a sulfonic acid in which the sulfonic acid radical is attached to a carbon atom other than the 9th or 10th. The structural composition of the compound 56 formed is shown in the following formula:

It is understood that in this formula, as shown, the sulfonic acid radical is indicated as being attached to the 11th carbon atom. It'might be attached to the 11th or the 17th carbon atom, or any intervening carbon atom. Likewise, it might be attached to the 2nd or 7th carbon atom or any intervening carbon atom. The formula is only illustrative. When a material such as shown in formula last mentioned is washed, hydrolysis may take place and the acid sulfate may decompose so that the acid sulfate radical is replaced by a hydroxyl radical. Such a compound is shown-in the following formula:

interpreted as being restricted to fatty sulfonic acids in their acidic state, insomuch as they may be equally suitable or preferable after neutralization with a basic material or after esterification with alcohol. Suitable bases for neutralization may be alkaline compounds of sodium, potassium, or ammonium. In some instances the calcium or magnesium salts formed by reaction with calcium .or magnesium hydroxide or carbonate show marked water solubility and sometimes even oil solubility. In either event, they are suitable for use. Alcohols suitable for esterification are ethyl, methyl, propyl, etc. The esters thus formed may be water-soluble or oil-soluble. In some instances, it may be desirable to neutralize the hydrogen of the sulfonic radical, but not the hydrogen of the carboxyl radical.

These compounds are most suitably prepared according to the procedure described in the Kalischer et al. Patent No. 1,835,404, previously referred to. Our preferred reagent or treating agent is prepared from the fatty acid sulfate of oleic acid. 100 parts of oleicacid are dissolved in about 125 parts of trichlorethylene, and treated with sufiicient sulfuric acid monohydrate so as to produce the fatty acid sulfate of oleic acid. This will ordinarily require about 30 parts of sulfuric acid monohydrate. The sulfation should take place at about/35 C. When the fatty acid sulfate of oleic acid has been produced, the entire reaction mass should be chilled to some point decidedly below 0 C., for instance, 5 to 15 below 0 C. The mixture should then be agitated and sulfur trioxide introduced into the reaction chamber in a gaseous form. The sulfur trioxide is permitted to react very slowly with constant agitation, and the temperature is controlled within the limits described. Approximately 50 parts of sulfur trioxide are required. At the completion of the reaction, the mass is washed with avery small quantity of cold water, so as to give a separation of the aqueous acid layer, which is drawn off. The remaining mixture containing the sulfo fatty body, trichlorethyleneand some free sulfuric acid, is neutralized with strong ammonia and permitted to stand until the ammonium sulfate present has separated out. The ammonium sulfate generally separates out in the form of a very concentrated solution, and can be drawn off.

The trichlorethylene solution of the sulfo fattyfatty acids, salts of petroleum sulfonic acids, and

the like.

The sulfonic acids thus produced, or in the form of salts or esters, will resolve or break oertain emulsions which may not be affected by fatty acid sulfates or the ordinary type of fatty sulfonic acid. The advantage or superiority of the reagent employed in our process is based on its ability to treat certain emulsions better than any other known reagent, and not on the basis that it can supersede the majority of modified fatty acids, sulfo fatty acids, etc. now used in the resolution of petroleum emulsions.

In practicing our process, a treating agent or demulsifying agent of the kind above described may be brought in contact with the emulsion to be treated in any of the numerous ways now employed in the treatment of petroleum emulsions 'of the water-in-oil type with chemical demulsifying agents, such, for example, as by introducing the treating agent into the well in which the emulsion is produced; introducing the treating agent into a conduit through which the emulsion is flowing; introducing the treating agent into a tank in which the emulsion .is stored; or

introducing the treating agent into a container emulsion is allowed to stand in a quiescent state, usually in a settling tank, and usualLv at a temperature varying from atmospheric temperature to about 200 F., so as to permit the water or brine to separate from the oil, it being preferable to keep the temperature low enough to prevent the volatilization of valuable constituents of the oil. If desired, the treated emulsion may be acted upon by one or more of the various kinds of apparatus now used in the operation of breaking petroleum emulsions, such as homogenizers, hay tanks, gun barrels, filters, centrifuges, or electrical dehydrators.

The amount of treating agent that may be required to break the emulsion may vary from approximately 1 part of treating agent to 500 parts of emulsion, up to 1 part of treating agent to 20,000 or even 30,000 parts of emulsion. The

' proportion depends on the type of emulsion beof the water -in-oil ing treated, and also upon the equipment being used, and the temperature-employed. In treatin'g exceptionally refractory emulsions of the kind residual pit oils", the ratio of 1:500, above referred to, may be required. In treating fresh emulsions, i. e., emulsions that will yield readily to the ical demulsifying agents, the ratio of 1:30,000,

above referred to, may be sumcient to producehighly satisfactory results.

In general, we have found petroleum emulsion, a ratio agent to 5000 parts of emulsion will usually be found to produce commercially satisfactory 're sults. Having thus described our invention, what we that for an average claim as new and desire to secure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-'in-oil type, which consists in subjecting'the emulsion to the action of a demulsifying agent containing a fatty sulfonic acid body, characterized by the fact that said fatty.sulfonic ,acid body is derived from a liquid commercial unsaturated fatty material having a single ethylene linkage, and that the sulfonic acid radical is attached to a carbon atom otherthan the conventionally reactive carbon atoms.

'2. A process for breaking petroleum emulsions ype. which consists insube'mulsion to the action of a demulsicontaininga salt of a fatty sulfonic characterized by the fact that said jecting the fying agent acid body,

fatty sulfonic acid body is derived from a liquid commercial unsaturated fatty material having a single ethylene linkage, and that the sulfonic acid radical is attached to a carbon atom other than the conventionally reactive carbon atoms.

3. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of agent containing-a water-soluble salt of a fatty action of chemof 1 part of treating a demulsifying characterized by the fact that said fatty sulfonic acid body is derived from a liquid commercial unsaturated fatty material having a single ethylene linkage, and that the sulfonic acid radical is attached to a carbon atom other than the conventionally reactive carbon atoms. a

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a fatty sulfonic acid body, characterized by the fact that said fatty sulfonic acid body is derived from ordinary oleic acid and that the sulfonic acid radical is attached to a carbon atom other than the conventionally reactive carbon atoms.

5.. A process for breaking petroleum emulsions of the'water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent containing a salt of a fatty sulfonic acid body, characterized by the fact that said fatty sulfonic acid body is derived from ordinary oleic acid and that-the sulfonic acid radical is attached to acarbon atom other than the conventionally reactive carbon atoms.

6. A process for breaking petroleum emulsions of thewater-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying, agent containing a water-soluble salt of a fatty sulfonic'acid body, characterized by the fact that said fatty sulfonic acid body is derived from ordinary .oleic acid and that the sulfonic acid radical is attached to a carbon atom other than sulfonic acid body,

. the conventionally reactive carbon atoms.

7. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent produced by reacting an unsaturated fatty acid body having a single ethylene linkage with sulfuric acid mono-hydrate andthen with gaseous sulfur trioxide, followed by a washing process and a neutralization process.

8. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent produced by reacting an unsaturated fatty acid body having a single ethylene linkage with sulfuric acid mono-hydrate and then with the gaseous sulfur trioxide, followed by a washing process and neutralization by means of strong ammonia. 1

9. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent produced by reacting oleic acid with sulfuric acid mono-hydrate and then with gaseous sulfur trioxide, followed by a washing process and a neutralization by means of strong ammonia.

MIELVIN DE GROOTE. 

